Through the December 2019 update, Yandex has been able to almost double to size of their index whilst also improving the speed and accuracy of delivery.
Initially rumored to be near 200-billion documents, the number of items in the index is not that large.
Yandex has bee able to achieve this scale through a clustering technique, to group similar items together.
Andrey Styskin, Head of Yandex Search, has said:
“At Yandex, it’s our goal to help consumers and businesses better navigate the online and offline world. With this new search update, users across the RuNet are helping us do just that. By contributing their knowledge, experts are enhancing our algorithms and helping our Search users, who continue to grow; over the past year, Yandex’s search share on Android in Russia rose 4.8% to 54.7% in early December.”
Doubling the size of the index has also aided Yandex’s machine learning capabilities. As disclosed on the official Yandex VK page:
[doubling the size of the index] helps to make up neural networks. Now there is everything at all – even super-rare pages
The machine learning elements, and “clusters” then allow Yandex to greatly increase the delivery speed of search results, as demonstrated by the below video, again shared by Yandex on their official VK page: